AbstractThe exploration of triboelectricity at the liquid–solid (L‐S) interface has sparked significant interest due to its potential for sustainable energy harvesting and technological advancement. Motivated by the need for innovative energy solutions and the unique advantages offered by liquid‐based environments, a comprehensive review of the fundamental concepts, mechanisms, and applications of liquid–solid triboelectric nanogenerators (TENGs) is provided. Three basic working modes of liquid–solid TENGs and the distinct properties and mechanisms of each model are discussed systematically. The physical fundamental of liquid–solid TENGs is further investigated, which includes “Wang Transition”, Wang's Hybrid Electric Double Layer model, tribovoltaic effect, equivalent circuit model, and the mechanisms of liquid–solid contact electrification based on density functional theory. Understanding charge transfer and charge distribution at the liquid–solid interface is also crucial to confirm the underlying mechanisms of liquid–solid TENGs. Finally, a broad range of applications of liquid–solid TENGs are explored, emphasizing their potential in addressing energy challenges and complex interdisciplinary issues that link the disciplines of materials science, chemistry, physics, and even electrical engineering.